Notification device for mobile unit

ABSTRACT

A notification device for a mobile unit according to an embodiment includes, for example: a storage unit that stores therein first sound data; a sound output control unit that outputs a notification sound based on the first sound data, from a sound output unit provided on the mobile unit; a generation unit that generates second sound data by performing predetermined processing on a location of sound falling, while causing the first sound data to follow a cycle of the notification sound, the predetermined processing being different from processing on a location of sound rising; and a light source drive control unit that causes a light source unit provided on the mobile unit to emit light in accordance with the intensity of a sound expressed by the second sound data.

TECHNICAL FIELD

Embodiments of the present invention relates to a notification devicefor a mobile unit.

BACKGROUND ART

Conventionally, mobile units, such as motorized wheelchairs, electricvehicles, and hybrid vehicles, have tended to be used widely. Thesemobile units are powered by motors that use electric power. Motorsproduce smaller sounds than engines and the like, so that, when themobile units are traveling, people around the mobile units may notnotice the presence thereof.

As a result, there have been developed technologies to make thesurroundings aware that a mobile unit is present by the mobile unitoutputting a sound. However, when a mobile unit outputs only a sound todraw attention, the sound needs to be output continuously or arelatively loud sound needs to be output so as not to be deadened bynoise and other sound, for example.

Thus, it is preferable to perform control so that sound output can bekept to some extent by combining sound with other elements instead ofoutputting only a sound. Other elements to be used may include light.However, simply outputting sound and light at the same time and notbringing light into agreement with sound may create a situation in whichthe level of risk emitted by a sound cannot be recognized with light,for example, which causes confusion. When sound and light are not inagreement with each other, a case is also conceivable as another examplein which, even if a person recognizes light, the person is not able torecognize that the output source of the particular light is the outputsource of sound.

In contrast, when a change in light is brought into agreement with theintensity of a sound, when a person visually identifies the change inlight, the person is able to recognize that the output source of theparticular light is the output source of the sound, for example. Asanother example, even in a situation in which a sound is heard onlyintermittently, when a person visually identifies light, the person isable to guess the intensity of the sound from a change in light, therebybeing able to grasp sound output.

Some technologies have been developed to output light in agreement withsound. These technologies tend to be used as an entertainment factor foran indicator or the like of a cellular phone, for example.

CITATION LIST Patent Literature

Patent Document 1: Japanese Patent Laid-open Publication No. 2004-205669

Patent Document 2: Japanese Patent Laid-open Publication No. 2002-141974

Patent Document 3: Japanese Patent Laid-open Publication No. 2004-282219

SUMMARY OF INVENTION Problem to be Solved by the Invention

However, conventional technologies are utilized for entertainment andthe like, and do not take into account a situation in which a mobileunit outputs light in agreement with sound. For example, when a sound isstopped, light is often stopped in sync with the sound in theconventional technologies.

In a case in which these conventional technologies are applied to amobile unit, when a sound is stopped, light is also stopped with thesound. In this case, when a person hears a sound falling and tries toidentify the output source of the sound, a situation occurs in whichlight is also stopped, for example. If such a situation occurs, it maybe difficult to identify the output source of the sound.

In other words, it is desired to perform control so that light output ismaintained to some extent while a sound is falling even in a case inwhich a mobile unit outputs light in accordance with the intensity ofthe sound. Consequently, a notification device is demanded that cannotify intuitively a person on board the mobile unit or pedestriansaround the mobile unit of a shift (an improving trend or a worseningtrend, for example) in the level of risk to operation performed by theperson on board.

Means for Solving Problem

A notification device for a mobile unit according to an embodimentincludes, for example: a storage unit that stores therein first sounddata; a sound output control unit that outputs a notification soundbased on the first sound data, from a sound output unit provided on themobile unit; a generation unit that generates second sound data byperforming predetermined processing on a location of sound falling,while causing the first sound data to follow a cycle of the notificationsound, the predetermined processing being different from processing on alocation of sound rising; and a light source drive control unit thatcauses a light source unit provided on the mobile unit to emit light inaccordance with an intensity of a sound expressed by the second sounddata. With this configuration, for example, when the light source unitemits light in sync with the notification sound, making processing atthe location of sound falling different from processing at the locationof sound rising causes people to recognize that the light and the soundcorrespond to each other, and then light emission control can beaccomplished that takes into account a lag from the time when peoplehear the sound to the time when they recognize the light. Thus, even ina case in which the sound cannot be caught, person on board orpedestrians around the mobile unit can intuitively grasp a temporalshift in the level of risk, only from the notification expression bymeans of light in the same manner as the notification by means of sound,thereby improving safety.

In the notification device for the mobile unit of the embodiment, forexample, when generating the second sound data from the first sounddata, the generation unit performs processing for repeating a sound of apredetermined period included in the notification sound, on the locationof sound falling. With this configuration, for example, repeating thesound of the predetermined period included in the notification soundcauses people to recognize that the light and the sound correspond toeach other, and then light emission control can be accomplished thattakes into account a lag from the time when people hear the sound to thetime when they recognize the light. Thus, pedestrians around the mobileunit can notice that the sound that has been output has been emittedfrom the mobile unit.

In the notification device for the mobile unit of the embodiment, forexample, the light source drive control unit changes at least one ormore of chroma and brightness of light emitted from the light sourceunit in sync with an intensity of a sound expressed by the second sounddata. With this structure, for example, by changing at least one or moreof chroma and brightness, a change in the light emitted from the lightsource unit in accordance with the cycle of the notification sound canbe noticed.

In the notification device for the mobile unit of the embodiment, forexample, the generation unit further generates the second sound data onwhich sound rising processing control and sound falling processingcontrol as the predetermined processing, the sound rising processingcontrol being performed in response to time passage during a soundrising period included in the cycle, the sound falling processingcontrol being performed in response to time passage during a soundfalling period included in the cycle, the sound falling processingcontrol bringing a smaller variation per unit of time than that duringthe sound rising period. With this configuration, for example, lightemission control can be accomplished that takes into account a lag fromthe time when people hear the sound to the time when they recognize thelight.

In the notification device for the mobile unit of the embodiment, forexample, the generation unit generates the second sound data on whichthe predetermined processing is performed, based on speed informationthat indicates a speed at which the mobile unit moves. With thisconfiguration, for example, light and sound can make the surroundingsaware of the speed of the mobile unit, thereby improving safety.

The notification device for the mobile unit of the embodiment furtherincludes an acquisition unit that acquires brightness information thatindicates brightness around the mobile unit, and the light source drivecontrol unit adjusts at least one or more of chroma and brightness oflight emitted by the light source unit, based on the brightnessinformation acquired by the acquisition unit. With this configuration,for example, light emission control of the light source unit can beaccomplished in accordance with the surrounding brightness, which makesit easy for the surroundings to be aware of the presence of the mobileunit with the light that is output from the light source unit, therebyimproving safety.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a mobile unit on which a light and soundoutput control device is mounted according to an embodiment;

FIG. 2 is a block diagram schematically illustrating a configuration ofthe light and sound output control device in the embodiment;

FIG. 3 is a view illustrating the shape of an envelope of a firstenvelope waveform used in a first envelope processing unit in theembodiment;

FIG. 4 is a view illustrating the shape of an envelope of a secondenvelope waveform used in a second envelope processing unit in theembodiment;

FIG. 5 is a view illustrating change information obtained by extractingchanges on the positive side of dummy sound data in FIG. 4;

FIG. 6 is a view illustrating combinations of brightness and chroma thatan information conversion unit calculates from values of the changeinformation on the basis of a predetermined linear relation, in theembodiment;

FIG. 7 is a view illustrating combinations of brightness and chroma thatan information conversion unit calculates from values of the changeinformation on the basis of a predetermined correlation, according tomodifications of the embodiment;

FIG. 8 is a view illustrating combinations of brightness and chroma thatan information conversion unit calculates from values of the changeinformation on the basis of a predetermined linear relation, in theembodiment;

FIG. 9 is a view illustrating light emission control of a light sourceunit performed by a light source drive control unit in the embodiment;

FIG. 10 is a flowchart illustrating a procedure to be followed up todrive control of a light source in the light and sound output controldevice in the embodiment;

FIG. 11 is a view illustrating the shape of an envelope of a secondenvelope waveform used in a second envelope processing unit according toa first modification;

FIG. 12 is a view illustrating the shape of an envelope of a secondenvelope waveform used in a second envelope processing unit according toa second modification;

FIG. 13 is a view illustrating the shape of an envelope of a secondenvelope waveform used in a second envelope processing unit according toa third modification; and

FIG. 14 is a view illustrating the shape of an envelope of a secondenvelope waveform used in a second envelope processing unit according toa fourth modification.

DESCRIPTION OF EMBODIMENTS

Exemplary embodiments of a notification device for a mobile unitaccording to the present invention will be described below.Configurations of the embodiments described below, and operations,results, and effects brought about by the configurations are onlyexamples. The present invention can also be accomplished byconfigurations other than those described in the embodiments below, andat least one of various effects based on the basic configurations andderivative effects can be achieved. In the embodiments below, an examplewill be described in which the notification device for a mobile unit isapplied to a light and sound output control device to be mounted on amobile unit.

A light and sound output control device 1 of an embodiment is mounted ona mobile unit. The mobile unit is a vehicle that a person can board, andcorresponds to a motorized wheelchair 100 in the present embodiment. Themobile unit will be described as the motorized wheelchair 100 below. Inthe present embodiment, the mobile unit is not limited to a vehicle thata person can board, and may be a mobile unit available fortransportation of a load, for example.

FIG. 1 is a perspective view of the mobile unit on which a light andsound output control device is mounted according to the embodiment. Asillustrated in FIG. 1, the motorized wheelchair 100 includes a seat 70,driving wheels 20, drive parts 30, an operation box 40, and a lightsource unit 50.

The seat 70 is provided by being pulled to a vehicle width direction.This seat 70 has a bottom 71 on which an occupant sits and a backrest 72on which the occupant leans while sitting on the bottom 71. The bottom71 and the backrest 72 are attached to frames 60 that constitute a bodyof the vehicle and are provided on both outer sides in the vehicle widthdirection. The motorized wheelchair 100 is collapsible along the vehiclewidth direction so as to facilitate storing and carrying the motorizedwheelchair 100. The seat 70 is made of folding cloth or a sheet ofvinyl.

Four wheels 25 are provided to the motorized wheelchair 100. The fourwheels 25 are made up of two casters 21 and two driving wheels 20. Thecasters 21 are provided on the front side in a traveling direction ofthe motorized wheelchair 100. The traveling direction is a direction inwhich the motorized wheelchair 100 moves forward. The casters 21 are apair of left and right casters arranged so as to face each other alongthe vehicle width direction. In FIG. 1, the caster 21 on the left sideis not illustrated.

The driving wheels 20 are provided on the rear side in the travelingdirection of the motorized wheelchair 100. The driving wheels 20 aremade up of a left driving wheel 20L and a right driving wheel 20Rarranged so as to face each other along the outer sides of the seat 70in the vehicle width direction. The left driving wheel 20L and the rightdriving wheel 20R will be described as the “driving wheels 20” belowunless they need to be distinguished from each other. The driving wheels20 are wheels to which power to drive the motorized wheelchair 100 istransmitted. Meanwhile, power is not transmitted to the casters 21,which are provided to support the front part of the motorized wheelchair100 in the present embodiment. The motorized wheelchair 100 also hasfall prevention bars 61L, 61R provided that extends toward the rear ofthe corresponding driving wheels 20 in order to prevent the seat 70 fromfalling over to the rear side in the traveling direction thereof. Thefall prevention bars 61L, 61R will be described as the “fall preventionbars 61” below unless they need to be distinguished from each other. Thefall prevention bars 61 serve as a regulatory means to prevent fallstoward the rear.

The drive parts 30 drive the respective driving wheels 20 by usingelectric power supplied from a battery 91. The battery 91 stores thereinelectric energy that powers the motorized wheelchair 100 in advance, andis attached via a holder 92 provided on the back of the backrest 72. Thedriving wheels 20 are a left driving wheel 20L and a right driving wheel20R. Thus, the drive parts 30 are provided as a pair so that the leftdriving wheel 20L and the right driving wheel 20R can be drivenindependently. Being driven independently means that the left drivingwheel 20L and the right driving wheel 20R can be driven at a rotationalspeed different from each other and in a rotational direction differentfrom each other. As a result, the drive parts 30 are made up of a leftdrive part 30L and a right drive part 30R as a pair. The left drive part30L and the right drive part 30R will be described as the “drive parts30” below unless they need to be distinguished from each other.

The left drive part 30L has a motor 32L that outputs a torque to causethe left driving wheel 20L to rotate. The right drive part 30R has amotor 32R that outputs a torque to cause the right driving wheel 20R torotate. The motor 32L and the motor 32R will be described as the “motors32” below unless they need to be distinguished from each other. Theelectric energy that is output from the battery 91 described above istransmitted to both the left drive part 30L and the right drive part30R, and drives the left driving wheel 20L and the right driving wheel20R independently of each other.

The operation box 40 includes a joystick 41 and a controller 42. Thejoystick 41 is provided to stand vertically upward in its neutral state.By the occupant of the motorized wheelchair 100 tilting the joystick 41from the state in a predetermined direction, the motorized wheelchair100 can be navigated in the tilted direction. The moving speed is alsoset in accordance with an angle at which the joystick 41 is tilted fromthe vertically upward position. The joystick 41, therefore, functions asan input device with which an intention of the occupant is input. Thecontroller 42 provides the drive parts 30 described above an instructionabout the input to the joystick 41. The controller 42, therefore,functions as a speed instruction unit that provides the drive parts 30an instruction about the set moving speed. The left drive part 30L andthe right drive part 30R that constitute the drive parts 30 respectivelydrive the motor 32L and the motor 32R on the basis of a drive commandconcerning traveling control that has been input via the joystick 41.

The light source unit 50 is a light source that emits light by using theelectric power supplied from the battery 91, and is fulfilled byarranging a plurality of LEDs in the interior of the light source unit50, for example. The light source unit 50 can also change at least oneor more of chroma and brightness in accordance with control from thelight and sound output control device 1.

The light and sound output control device 1 is described next. FIG. 2 isa block diagram schematically illustrating a configuration of the lightand sound output control device 1 in the embodiment. The light and soundoutput control device 1 includes a sound data storage unit 201 on astorage (an SSD, for example) not illustrated. Furthermore, a CPU notillustrated executes a computer program stored in the storage, wherebythe light and sound output control device 1 includes, on a RAM notillustrated, a speed information acquisition unit 202, a person'sinformation input unit 203, a pace computation unit 204, a notificationcycle setting unit 205, a notification sound output control unit 206, adummy sound generation unit 207, an information acquisition unit 208, aninformation conversion unit 209, and a light source drive control unit210. FIG. 2 also illustrates the driving wheels 20, the drive parts 30,the motors 32, and the controller 42 described above.

The sound data storage unit 201 stores therein sound data. The sounddata of the present embodiment is waveform data describing sound in apredetermined waveform. In the present embodiment, the shape of thewaveform is not particularly limited, and any shape may be possible. Thesound data stored in the sound data storage unit 201 is stored as sounddata in which the time that a sound is output is longer than the timethat the sound is actually output. With this configuration, even in acase in which dummy sound data is processed into an envelope waveform,the sound data can be prevented from being lost.

The speed information acquisition unit 202 acquires speed informationthat indicates the moving speed of the motorized wheelchair 100. Themoving speed is detected based on the number of revolutions of thedriving wheels 20. As described above, the motorized wheelchair 100includes the left driving wheel 20L and the right driving wheel 20R,which are driven independently of each other. Because the left drivingwheel 20L and the right driving wheel 20R do not always rotate in thesame manner, a rotation sensor 11L that detects the number ofrevolutions of the left driving wheel 20L and a rotation sensor 11R thatdetects the number of revolutions of the right driving wheel 20R areincluded in the present embodiment.

The speed information acquisition unit 202 acquires, from the rotationsensor 11L and the rotation sensor 11R, a detection result on the numberof revolutions of the left driving wheel 20L and the right driving wheel20R, and detects (computes) the moving speed of the motorized wheelchair100 by using the acquired number of revolutions. The speed informationacquisition unit 202 outputs the detected moving speed as the speedinformation to the pace computation unit 204.

A method of acquiring the speed information is not limited to the methodof acquiring the speed information from the rotation sensors 11L, 11R.For example, because the controller 42 functions as the speedinstruction unit that provides the drive parts 30 an instruction aboutthe moving speed in response to operations of the joystick 41, the speedinformation acquisition unit 202 may acquire instruction details on themoving speed provided by the controller 42 and output, to the pacecomputation unit 204, the moving speed included in the instructiondetails as the speed information.

The person's information input unit 203 receives input of information ona person who is on board the motorized wheelchair 100. For example, theperson's information input unit 203 receives input of the height of theperson who is on board. The person's information input unit 203 mayreceive input of the age and sex as needed.

The pace computation unit 204 computes a pace at which the person moveswith a cyclic motion, from the moving speed indicated by the speedinformation that has been input from the speed information acquisitionunit 202. The pace at which the person moves with a cyclic motion is apace of a person when the person is assumed to have moved at the movingspeed acquired by the speed information acquisition unit 202. The pacerefers to a rate at which a person moves, and is made up of the numberof steps per unit of time in the present embodiment. The pace means notonly a rate at which a person walks, but also includes a rate at whichthe person runs in the present embodiment.

The walking speed of a person is determined by the product of a strideand a pace. The stride is generally said to be a value obtained bysubtracting 100 cm from the person's height. The pace is the number ofsteps per unit of time (1 second, for example), as described above.Thus, the pace computation unit 204 calculates the pace by dividing themoving speed indicated by the speed information that has been input fromthe speed information acquisition unit 202 by the stride in accordancewith the height of the person who is on board the motorized wheelchair100 (the input of which has been received by the person's informationinput unit 203). When the pace is calculated, the age and sex may alsobe taken into account, in addition to the height. Although the examplehas been described in which a pace is used as information indicating themoving speed in the present embodiment, the information is not limitedto the pace and any cyclic motion that a person makes while walking (awave of the hand, a shake of the face, and a swing of the hips, forexample) may be possible.

The notification cycle setting unit 205 sets a notification cycle bywhich the presence of the motorized wheelchair 100 is notified thesurroundings on the basis of the pace computed by the pace computationunit 204. The notification cycle setting unit 205 sets the reciprocal ofthe pace computed by the pace computation unit 204 for the notificationcycle.

In the present embodiment, a sound and light in accordance with thenotification cycle are combined and output in order to notify thesurroundings of the presence of the motorized wheelchair 100.

The notification cycle is a cycle by which the light and sound outputcontrol device 1 notifies the surroundings of the presence of themotorized wheelchair 100. A notification period during whichnotification is provided and a quiescent period during whichnotification is stopped are specified within one cycle of thenotification cycle in the present embodiment. The notification cyclethat has been set by the notification cycle setting unit 205 is outputto the notification sound output control unit 206.

The notification sound output control unit 206 includes a first envelopeprocessing unit 211. After the sound data is read from the sound datastorage unit 201, the notification sound output control unit 206generates, from the sound data, notification sound data in accordancewith the notification cycle that has been set by the notification cyclesetting unit 205. The notification sound output control unit 206 thenoutputs the generated notification sound data from a speaker 17 providedto the motorized wheelchair 100. The notification sound data isgenerated by the first envelope processing unit 211.

The first envelope processing unit 211 performs first processing on thesound data read from the sound data storage unit 201 by using anenvelope generator, and generates notification sound data indicated by afirst envelope waveform. The first processing of the present embodimentis processing for cutting out the sound data in an envelope patternindicating the first envelope waveform.

FIG. 3 is a view illustrating the shape of an envelope of the firstenvelope waveform used in the first envelope processing unit 211 in theembodiment. The envelope of the first envelope waveform illustrated inFIG. 3 is formed in accordance with the notification cycle. In otherwords, the envelope of the first envelope waveform of the presentembodiment includes a notification period (time t10 to time t11, forexample) and a quiescent period (time t11 to time t12, for example) forevery cycle of the notification cycle (time t10 to time t12, forexample).

The first envelope processing unit 211 generates the notification sounddata in accordance with the envelope of the envelope waveformillustrated in FIG. 3, so that, after output of a notification soundfrom the speaker 17 is repeated four times (the first time: time t10 totime t11; the second time: time t12 to time t13; the third time: timet14 to time t15; and the fourth time: time t16 to time t17), the lightand sound output control device 1 performs control so as to stop theoutput of the notification sound.

The notification sound output control unit 206 then outputs, from thespeaker 17, the notification sound data generated by the first envelopeprocessing unit 211. The output of the notification sound data by thenotification sound output control unit 206 is timed to drive control ofthe light source unit 50 by the light source drive control unit 210described later.

In the present embodiment, the envelope waveform of the notificationsound is not limited to the shape illustrated in FIG. 3, and othershapes may be possible. For example, an envelope waveform that brings “asense of alarm” may be used depending on the status of the mobile unit,or an envelope waveform that brings “a sense of luxury” and “acomfortable feeling” may be used considering a user who is on board themobile unit.

By the way, because the notification sound is susceptible to the noisestatus of the surroundings, the person on board or pedestrians aroundthe mobile unit cannot always catch the notification sound that isoutput from the motorized wheelchair 100. Turning up the volume of thenotification sound or increasing the frequency of outputting thenotification sound can improve the ease of catching the sound, whichalso incurs the risk of bothering the person on board or the pedestriansaround the mobile unit. Consequently, it has been decided in the presentembodiment to perform drive control to change at least one or more ofbrightness and chroma of the light source unit 50 in accordance with theintensity of the notification sound when the notification sound isoutput. with this configuration, when visually identifying a change inthe light that has been output from the light source unit 50, thepedestrians around the motorized wheelchair 100 are able to grasp thesound that is in sync with the change in the light and that is outputfrom the speaker 17.

The dummy sound generation unit 207 includes a second envelopeprocessing unit 212. After the sound data is read from the sound datastorage unit 201, the dummy sound generation unit 207 performs secondprocessing on the sound data in accordance with the notification cyclethat has been set by the notification cycle setting unit 205, andgenerates dummy sound data.

The dummy sound data is not sound data that is output from the speaker17, but is sound data used to control the change in the light that isoutput from the light source unit 50. In other words, it has beendecided in the present embodiment not to use the notification sound datathat is output from the notification sound output control unit 206, butto use the dummy sound data that is generated by the dummy soundgeneration unit 207 when performing drive control of the light that isoutput from the light source unit 50. The dummy sound data, which issound data in accordance with the notification cycle, is also in syncwith the notification sound data.

The second envelope processing unit 212 generates dummy sound dataindicated by a second envelope waveform by using an envelope generatorthat performs second processing.

The second envelope processing unit 212 of the present embodiment cutsout the sound data in an envelope pattern indicating the second envelopewaveform by using the envelope generator that performs secondprocessing. In the envelope pattern indicating the second envelopewaveform, a location of sound falling and a location of sound risinghave waveforms different from each other, that is to say, differentprocessing is performed. More specifically, the envelope patternindicating the second envelope waveform is a pattern that includes suchchanges that the sound becomes louder as time passes during a soundrising period, whereas the sound becomes softer as time passes during asound falling period. Additionally, the envelope pattern is a pattern inwhich the absolute value of a derivative value of a variation during thesound rising period is larger than the absolute value of a derivativevalue of a variation during the sound falling period.

The envelope pattern indicating the second envelope waveform uses such apattern that the intensity of a sound changes as time passes, whichmakes the waveform smoother than the envelope pattern (indicating thefirst envelope waveform) of the notification sound. As a result,performing drive control of the light source unit 50 on the basis of thedummy sound data enables improved visual recognizability and can alsoproduce the effect of reducing flashing of the light to prevent glare.

FIG. 4 is a view illustrating the shape of an envelope of the secondenvelope waveform used in the second envelope processing unit 212 in theembodiment. The envelope of the second envelope waveform illustrated inFIG. 4 is formed in accordance with the notification cycle in the samemanner as the first envelope waveform. In other words, the envelope ofthe second envelope waveform of the present embodiment includes a soundrising period (time t10 to time t11, for example) and a sound fallingperiod (time t11 to time t12, for example) for every cycle of thenotification cycle (time t10 to time t12, for example). Additionally,the normal sound rising period (time t10 to time t11, for example)corresponds to a notification period, and the sound falling period (timet11 to time t12, for example) corresponds to a quiescent period.

The second envelope waveform has such an envelope that a period isformed during which the sound rises abruptly so as to correspond to thenotification period of the notification sound data and that a period isalso formed during which the sound falls gently so as to correspond tothe quiescent period.

The second envelope processing unit 212 uses the second envelopewaveform described above, thereby generating the dummy sound data onwhich sound rising processing control has been performed in response totime passage during the sound rising period (time t10 to time t11, forexample) included in the notification cycle, and sound fallingprocessing control has also been performed in response to time passage,with a smaller variation per unit of time than that during the soundrising period, during the sound falling period (time t11 to time t12,for example) included in the notification cycle and the sound fallingperiod (time t17 to time t18, for example) after notification isfinished.

Thus, the second envelope waveform has such an envelope that a change ismade more gently at the location of sound falling than the location ofsound rising. Furthermore, the second envelope waveform has such anenvelope that the sound falls still more gently at the location of soundfalling after notification using the notification sound data is finished(time t17, for example) than that during the normal sound rising period.With this configuration, the dummy sound data has the sound continuouslyfalling over an extended time period from time t17 to time t18, as theexample illustrated in FIG. 4 in the present embodiment.

The second envelope processing unit 212 generates the notification sounddata in accordance with the envelope of the envelope waveformillustrated in FIG. 4, so that, after processing to change at least oneor more of brightness and chroma of the light from the light source unit50 is repeated four times (the first time: time t10 to time t11; thesecond time: time t12 to time t13; the third time: time t14 to time t15;and the fourth time: time t16 to time t17), the light and sound outputcontrol device 1 performs control so as to decrease at least one or moreof brightness and chroma of the light during a predetermined period(time t17 to time t18, for example).

In the present embodiment, the notification sound and the light of thelight source unit 50 are in agreement with each other in that they areoutput in accordance with the notification cycle. However, thenotification sound and the light of the light source unit 50 aredifferent from each other in that the sound is clearly switched betweenon and off, whereas the light is gradually changed instead of beingclearly switched between on and off.

In other words, control to increase at least one or more of brightnessand chroma of the light is performed during the sound rising period ofthe dummy sound data, and control to decrease at least one or more ofbrightness and chroma of the light is performed during the sound fallingperiod of the dummy sound data in the present embodiment.

In doing so, by using the dummy sound data described above, the controlto decrease at least one or more of brightness and chroma of the lightchanges more gently than the control to increase at least one or more ofbrightness and chroma of the light does.

As a result, a long time is required from the time at which thenotification sound is turned off (time t17, for example) to the time atwhich the light completely goes out (time t18, for example). In thepresent embodiment, by performing this control, even after the motorizedwheelchair 100 has stopped output of the notification sound, peoplearound the motorized wheelchair 100 can see the light going out, so thatthey can guess that the motorized wheelchair 100 was outputting thenotification sound.

Conventionally, there have been developed technologies to display thesound level in real time by means of light by an indicator or the likeof a cellular phone, for example. Given that the indicator displays thesound level in real time by means of light, if light output ismaintained after a sound is stopped, sound and light are not inagreement with each other, thereby providing a feeling that something iswrong. In other words, conventional technologies do not take intoaccount controlling light output with transient response characteristics(a time constant) that deviate greatly from loudness characteristics ofa person.

In contrast, even after the notification sound continues to fall and isstopped, the light output from the light source unit 50 is maintained inthe light and sound output control device 1 of the present embodiment.In the present embodiment, light is used not to display the sound levelin real time, but to enable people to recognize the presence of theoutput source of the notification sound (the mobile unit, for example).For this reason, it is decided that, even after the sound continues tofall and is stopped, the light output from the light source unit 50 ismaintained.

The information acquisition unit 208 acquires, from a photosensor 18,brightness data that indicates the brightness around the motorizedwheelchair 100.

The information conversion unit 209 converts the dummy sound datagenerated by the dummy sound generation unit 207 into light control datato be output from the light source unit 50.

The information conversion unit 209 of the present embodiment convertsthe intensity of the sound of the dummy sound data into a combination ofbrightness and chroma of light. The information conversion unit 209 ofthe present embodiment performs a conversion on the basis of thebrightness data acquired by the information acquisition unit 208.

FIG. 5 is a view illustrating change information obtained by extractingchanges on the positive side of the dummy sound data in FIG. 4. In theexample illustrated in FIG. 5, the information conversion unit 209extracts changes on the positive side of the dummy sound data, and usesthe changes on the positive side as change information for adjustment ofthe brightness and chroma of the light from the light source. In thechange information of the present embodiment, the minimum value of thedummy sound data is set at 0%, and the maximum value of the dummy sounddata is set at 100%.

Furthermore, the information conversion unit 209 sets a range of thecombination of brightness and chroma that can be adjusted by the lightsource unit 50, on the basis of the brightness data acquired by theinformation acquisition unit 208.

The information conversion unit 209 of the present embodiment sets alower limit of the brightness that can be adjusted by the light sourceunit 50, on the basis of the brightness data acquired by the informationacquisition unit 208. In the present embodiment, a minimal brightnesswith which people around the motorized wheelchair 100 can visuallyidentify the light of the light source unit 50 with the surroundingbrightness based on the brightness data is set as the lower limit of thebrightness of the light source unit 50. Specific brightness is to be setaccording to the implementation.

FIG. 6 is a view illustrating combinations of brightness and chroma thatthe information conversion unit 209 calculates from values of the changeinformation on the basis of a predetermined linear relation. FIG. 6illustrates an example in which the lower limit of the brightness is setat 20% on the basis of the brightness data acquired by the informationacquisition unit 208. The information conversion unit 209 calculates acombination of brightness and chroma that corresponds to the intensityof the sound of the dummy sound data by substituting a value (from 0% to100%) of the change information into a function that expresses a linearrelation from 20% in brightness and 0% in chroma to 100% in brightnessand 100% in chroma.

The example in FIG. 6 illustrates combinations of brightness and chromathat correspond to the values (45%, 70%, 90%, 100%) of the changeinformation in FIG. 5. The information conversion unit 209 of thepresent embodiment can derive a combination of brightness and chromathat corresponds to the notification sound data by performing theprocessing described above.

The present embodiment is not limited to using the function based on thelinear relation when a combination of brightness and chroma iscalculated, as long as there is a correlation between values of thechange information and combinations of brightness and chroma.

FIG. 7 is a view illustrating combinations of brightness and chroma thatthe information conversion unit 209 calculates from values of the changeinformation on the basis of a predetermined correlation, according tomodifications of the embodiment. In the example illustrated in FIG. 7, alength with 0% in chroma and 20% in brightness as the starting point ona line expressed by a logarithmic function is correlated with a value ofthe change information, whereby a combination of brightness and chromais calculated from the value of the change information.

The description now returns to the first embodiment, and a case will bedescribed in which the surrounding brightness differs from that in FIG.6. FIG. 8 is a view illustrating combinations of brightness and chromathat the information conversion unit 209 calculates from values of thechange information on the basis of a predetermined linear relation, inthe embodiment. FIG. 8 illustrates an example in which the surroundingsof the motorized wheelchair 100 is brighter than the situationillustrated in FIG. 6, so that the lower limit of the brightness is setat 60% on the basis of the brightness data acquired by the informationacquisition unit 208. The information conversion unit 209 calculates acombination of brightness and chroma that corresponds to the intensityof the sound of the dummy sound data by substituting a value (from 0% to100%) of the change information into a function that expresses a linearrelation from 60% in brightness and 0% in chroma to 100% in brightnessand 100% in chroma.

The light source drive control unit 210 performs light emission controlof the light source unit 50 provided to the motorized wheelchair 100, inaccordance with the combination of brightness and chroma that has beencalculated by the information conversion unit 209. Given that thecombination of brightness and chroma calculated by the informationconversion unit 209 is derived from the intensity of the sound expressedby the dummy sound data, the light source drive control unit 210performs control so as to change at least one or more of chroma andbrightness of the light emitted from the light source unit 50 in syncwith the intensity of the sound expressed by the dummy sound data.

Additionally, given that the light source drive control unit 210performs drive control of the light source unit 50 by the combination ofbrightness and chroma calculated on the basis of the brightness by theinformation conversion unit 209, the light source drive control unit 210adjusts at least one or more of chroma and brightness of the lightemitted by the light source unit 50 on the basis of the brightness dataacquired by the information acquisition unit 208.

The light source drive control unit 210 of the present embodimentperforms light emission control of the light source unit 50 in sync withthe output of the notification sound data by the notification soundoutput control unit 206.

FIG. 9 is a view illustrating light emission control of the light sourceunit 50 performed by the light source drive control unit 210 in theembodiment. In the example illustrated in FIG. 9, drive control of thelight source unit 50 is performed in correspondence with the intensityof the sound of the dummy sound data illustrated in FIG. 4. For example,during the period of sound rising from time t10 to t11 illustrated inFIG. 4, drive control is performed so that the light emitted from thelight source unit 50 becomes bright in FIG. 9. During the period ofsound falling from time t11 to t12 illustrated in FIG. 4, drive controlis performed so that the light emitted from the light source unit 50becomes dark in FIG. 9. By performing drive control of light asillustrated in FIG. 9, such drive control can be accomplished as tomaintain a state in which, after drive control of the light has beenbrought into sync with the notification sound, even if the notificationsound is stopped, the light is not stopped with the brightness andchroma of the light decreasing.

A process up to drive control of the light source in the light and soundoutput control device 1 of the present embodiment is described next.FIG. 10 is a flowchart illustrating a procedure of the process describedabove in the light and sound output control device 1 in the embodiment.

The speed information acquisition unit 202 outputs the moving speed ofthe motorized wheelchair 100 as speed information to the pacecomputation unit 204 (S1001).

The pace computation unit 204 calculates a pace of a person on the basisof the speed information that has been input from the speed informationacquisition unit 202 (S1002).

The notification cycle setting unit 205 sets a notification cycle bywhich the presence of the motorized wheelchair 100 is notified thesurroundings on the basis of the pace computed by the pace computationunit 204 (S1003).

The first envelope processing unit 211 of the notification sound outputcontrol unit 206 generates notification sound data indicated by thefirst envelope waveform in accordance with the notification cycle, forthe sound data read from the sound data storage unit 201 (S1004). Thefirst envelope waveform is the same as the waveform described above, andthe description thereof is omitted.

The second envelope processing unit 212 of the dummy sound generationunit 207 then generates dummy sound data indicated by the secondenvelope waveform in accordance with the notification cycle, for thesound data read from the sound data storage unit 201 (S1005). The secondenvelope waveform is the same as the waveform described above, and thedescription thereof is omitted.

The information conversion unit 209 extracts, from the dummy sound datagenerated by the dummy sound generation unit 207, change informationthat indicates changes in the intensity of the sound on the positiveside of the dummy sound data (S1006).

Meanwhile, the information acquisition unit 208 acquires, from thephotosensor 18, brightness data that indicates the brightness around themotorized wheelchair 100 (S1007).

The information conversion unit 209 then generates light control data ofthe light source unit 50 in which chroma and brightness are combinedfrom the extracted change information and the brightness data (S1008).

The notification sound output control unit 206 then outputs thenotification sound data generated at S1004 to the speaker 17 (S1009).

Meanwhile, the light source drive control unit 210 performs drivecontrol of the light source unit 50 in accordance with the control datain which chroma and brightness are combined and that has been calculatedby the information conversion unit 209 (S1010). Starting drive controlof the light source unit 50 is timed to the notification sound outputcontrol unit 206 starting output of the notification sound data. Withthis configuration, the light and the output of the notification soundcan be brought into sync with each other.

It has been decided in the present embodiment to change the combinationof chroma and brightness of the light from the light source unit 50 inconjunction with the intensity of the notification sound. In the presentembodiment, combinations of chroma and brightness are tied to theintensity of the notification sound, thereby enabling detailed parametercontrol in conjunction with sound. With this configuration, visualrecognizability of continuous changes can be improved.

However, the present embodiment is not limited to an example in whichcombinations of chroma and brightness are used, as long as a continuouschange in light is used. For example, at least one of chroma andbrightness may be used, or hue or the like may be combined.Alternatively, other color spaces may be used instead of performingcontrol by using the HSV color space consisting of chroma, brightness,and color phase. Furthermore, a gamma value or color temperature, forexample, may be used as color representation.

In the present embodiment, the example has been described in which anotification cycle is set on the basis of a pace calculated from speedinformation that indicates the speed at which the motorized wheelchair100 moves, and dummy sound data in which the sound falling time isadjusted is generated on the basis of the notification cycle. However,the present embodiment is not limited to a method of generating dummysound data on the basis of a notification cycle based on a pace, and anymethod may be used by which dummy sound data is generated on the basisof the speed information that indicates the speed at which the motorizedwheelchair 100 moves.

In the present embodiment, the example has been described in which alower limit (offset) of brightness at which the light source unit 50outputs is set on the basis of brightness information that indicates thesurrounding brightness. However, the present embodiment is not limitedto a method of setting a lower limit of brightness at which the lightsource unit 50 outputs on the basis of brightness information, and anymethod may be used by which at least one or more of chroma andbrightness of the light emitted by the light source unit 50 is adjustedon the basis of the brightness information, thereby enabling thesurroundings to recognize the light of the light source unit 50.

Additionally, the example has been described in which a lower limit(offset) of brightness is set on the basis of the brightness informationin the present embodiment. However, the present embodiment is notlimited to a method of setting a lower limit (offset) of brightness andchroma in accordance with the surrounding brightness, and the lowerlimit may be set in accordance with other elements. A lower limit(offset) of brightness and chroma may be set in accordance with thetraveling position and speed of the motorized wheelchair 100, forexample.

<First Modification>

In the embodiment described above, the case has been described in whichthe dummy sound data as illustrated in FIG. 4 is generated. However, theembodiment described above is not limited to generating the dummy sounddata as illustrated in FIG. 4.

FIG. 11 is a view illustrating the shape of an envelope of the secondenvelope waveform used in the second envelope processing unit 212according to the first modification. The envelope of the second envelopewaveform illustrated in FIG. 11 is formed in accordance with thenotification cycle in the same manner as that of the embodimentdescribed above. In other words, the envelope of the second envelopewaveform of the present embodiment is formed so that the intensity ofthe sound increases from ‘0’ during the sound rising period (time t10 totime t11, for example), and the sound rises again from an intensity ofthe sound of ‘0’ after the sound falling period (time t11 to time t12,for example) is finished, for one cycle of the notification cycle (timet10 to time t12, for example).

<Second Modification>

In the embodiment and the first modification described above, processingis performed so that the sound falling time of the dummy sound data islonger than that of the notification sound data. However, the embodimentand the first modification are not limited to the processing describedabove, and what is called audio effect processing may be added so thatthe sound falling time is further increased greatly. Thus, a case isdescribed in which delay is used when the dummy sound data is generatedin the second modification. Delay is processing in which a copy sound ofthe notification sound is repeated while being attenuated at regularintervals.

The second envelope processing unit 212 of the present modificationperforms processing for repeating the sound of a predetermined periodincluded in the notification sound data, on the location of soundfalling of the dummy sound data when the dummy sound data is generatedfrom the sound data stored in the sound data storage unit 201. Anenvelope waveform for performing the processing is described next.

FIG. 12 is a view illustrating the shape of an envelope of the secondenvelope waveform used in the second envelope processing unit 212according to the second modification. Delay, which is a type of audioeffect processing, is performed on the envelope of the second envelopewaveform illustrated in FIG. 13. By performing drive control of thelight source unit 50 in accordance with the dummy sound data, lightemission control of the light source unit 50 is performed by the samenotification cycle as that of the notification sound even after thenotification sound is stopped.

In the present modification, the cycle by which the delay changes thelight of the light source unit 50 is the same as the notification cycleof the notification sound. As a result, when visually identifying thelight of the light source unit 50, people around the motorizedwheelchair 100 can guess that the output source of the notificationsound is the motorized wheelchair 100 even after the notification soundis stopped.

<Third Modification>

In the second modification described above, the case has been describedin which delay is used when the dummy sound data is generated. However,the audio effect processing is not limited to the delay. Thus, a case isdescribed in which reverb is used when the dummy sound data is generatedin the third modification. Reverb is processing in which a reverberantsound obtained by artificially reproducing the notification sound isrepeated while being attenuated at regular intervals.

FIG. 13 is a view illustrating the shape of an envelope of the secondenvelope waveform used in the second envelope processing unit 212according to the third modification. Reverb, which is a type of audioeffect processing, is performed on the envelope of the second envelopewaveform illustrated in FIG. 13. By performing drive control of thelight source unit 50 in accordance with the dummy sound data, lightcontrol of the light source unit 50 is performed by the samenotification cycle as that of the notification sound even after thenotification sound is stopped. With this configuration, the same effectas that of the second modification can be obtained.

In the second modification and the third modification, a spatial effect(delay and reverb, for example) is used, thereby repeating the lightobtained by reproducing a pattern of the intensity of the notificationsound in accordance with the changed combination of brightness andchroma, which enables people around the motorized wheelchair 100 torecognize, by means of light, the output source of the sound that theyhave heard earlier. Because the change in the light is repeated comparedwith the embodiment described above, the effect can also be produced ofpeople around the motorized wheelchair 100 easily noticing the change.

<Fourth Modification>

In the second modification and the third modification described above,the case has been described in which a spatial effect (delay and reverb,for example) is used when the dummy sound data is generated. However,the audio effect processing is not limited to the spatial effect (delayand reverb). Thus, a case is described in which a compressor, which is adynamic range control effect, is used when the dummy sound data isgenerated in the fourth modification. A compressor is processing inwhich, after the difference between a big sound and a small sound of thenotification sound is reduced, the notification sound is repeated whilebeing attenuated at regular intervals.

FIG. 14 is a view illustrating the shape of an envelope of the secondenvelope waveform used in the second envelope processing unit 212according to the fourth modification. Compressor processing, which is atype of audio effect processing, is performed on the envelope of thesecond envelope waveform illustrated in FIG. 14. By performing drivecontrol of the light source unit 50 in accordance with the dummy sounddata, light control of the light source unit 50 is performed by the samenotification cycle as that of the notification sound even after thenotification sound is stopped.

Although the case is described in which a compressor is used as adynamic range control effect in the fourth modification, other effects(a gate and a limiter, for example) may also be used.

In the present modification, by reducing the difference between a bigsound and a small sound, the difference in dynamic ranges between soundand light can be reduced. Because the change in the light iscontinuously repeated compared with a case in which the change in thelight is smoothly falls, the effect can be produced of people around themotorized wheelchair 100 easily noticing the change.

<Fifth Modification>

In the present embodiment and the modifications, the examples have beendescribed in which notification sound data and dummy sound data aregenerated by using an envelope pattern according to the notificationcycle based on the pace. However, the present embodiment and themodifications are not limited to using the notification cycle based onthe pace when the notification sound data and the dummy sound data aregenerated. For example, the level of risk to operation performed by theperson on board the motorized wheelchair 100 may be expressed by thenotification sound data. Thus, an example is described in which thenotification sound data is output considering the level of risk in thepresent modification.

In the present modification, the notification sound output control unit206 acquires the level of risk to the operation performed by the personon board the motorized wheelchair 100. The notification sound outputcontrol unit 206 then generates the notification sound data in responseto the level of risk. As a method of generating the notification sounddata in response to the level of risk, any generating method may be usedregardless of whether the method is a well-known technology. Forexample, varying the shape of the envelope waveform in response to thelevel of risk is conceivable.

The process subsequent to generation of the dummy sound data is the sameas that of the embodiment and the description thereof is omitted.

In the present modification, a shift (“an improving trend”/“a worseningtrend”) in the level of risk to the operation performed by the person onboard the mobile unit can be notified intuitively the person on board orpedestrians around the mobile unit not only by the notification soundbut also by means of light. Thus, the person on board or pedestriansaround the mobile unit can grasp the level of risk by means of the lightof the light source unit 50 even in a case in which the sound cannot beheard because of noise. With this configuration, safety can be improved.

In the embodiment and the modifications described above, it has beendecided that, when the notification sound is output, the chroma andbrightness of the light of the light source unit 50 are changed inconjunction with the intensity of the notification sound or on/off ofthe sound. Performing control so as to maintain the light of the lightsource unit 50 while the notification sound falls can cause peoplearound the motorized wheelchair 100 to notice the presence of themotorized wheelchair 100.

In the embodiment and the modifications described above, the exampleshave been described in which an electric wheelchair is used as a mobileunit. However, the mobile unit is not limited to an electric wheelchairin the present embodiment, and other mobile units may be possible. Anexample of the mobile unit may include a single-passenger personalmobility vehicle. Additionally, the personal mobility vehicle is notlimited to a vehicle that a person can board, and may be intended totransport a load, for example.

Furthermore, the mobile unit may be an automobile and the like. In acase in which the mobile unit is an automobile and the like, the outputdestination of the notification sound may be surroundings of theautomobile and the like, or may be the interior of the automobile andthe like. A light and sound output control device provided in theinterior of the automobile and the like causes a light source unitprovided in the vicinity of a speaker to glow when outputting anotification sound, thereby enabling a person on board to recognize theoutput source of the notification sound.

In the embodiment and the modifications described above, it has beendecided that, when a change in the light that is output from the lightsource unit 50 is brought into sync with the notification sound, notonly the notification sound data but also dummy sound data the soundfalling time of which is set to be longer than that of the notificationsound data are generated, and drive control of a change in the light ofthe light source unit 50 is performed in correspondence with the dummysound data.

In the embodiment and the modifications described above, even if thesurroundings of the motorized wheelchair 100 are an environment wherethe noise environment and the lighting environment vary greatly,producing intuitive output by utilizing sound and light in acomplementary manner enables people around and an operator of themotorized wheelchair 100 to gain an appropriate awareness of themotorized wheelchair 100. This can lead to a margin of safety behavior.

In the embodiment and the modifications described above, even in a casein which the notification sound cannot be caught, the light of the lightsource unit 50 is changed in response to the notification sound, so thatthe same content as that of the notification by means of sound can begrasped intuitively.

In the embodiment and the modifications described above, the rhythm ofthe notification sound can be perceived with a pattern of the change inthe light that is output form the light source unit 50. As a result, byvisually identifying the pattern of the change in the light that isoutput form the light source unit 50, a change in the intensity of thesound can also be noticed. Consequently, the ease of catching thenotification sound can be improved.

In the embodiment and the modifications described above, it has beendecided that processing is performed so that the falling time of thelight is longer than that of the sound while utilizing the sound and thelight in a complementary manner, instead of drawing attention by usingthe light that is output from the light source unit 50. With thisconfiguration, even after the sound is stopped, the light is caused tolinger, so that control can be accomplished that takes into account atime lag from when people around the motorized wheelchair 100 hear thesound to when they visually identify the light.

While certain embodiments of the present invention have been described,these embodiments have been presented by way of example only, and arenot intended to limit the scope of the inventions. These novelembodiments may be embodied in a variety of other forms, and variousomissions, substitutions, and changes may be made without departing fromthe spirit of the inventions. The accompanying claims and theirequivalents are intended to cover these embodiments or modificationsthereof as would fall within the scope and spirit of the inventions.

1. A notification device for a mobile unit, the notification device comprising: a storage unit that stores therein first sound data; a sound output control unit that outputs a notification sound based on the first sound data, from a sound output unit provided on the mobile unit; a generation unit that generates second sound data by performing predetermined processing on a location of sound falling, while causing the first sound data to follow a cycle of the notification sound, the predetermined processing being different from processing on a location of sound rising; and a light source drive control unit that causes a light source unit provided on the mobile unit to emit light in accordance with an intensity of a sound expressed by the second sound data.
 2. The notification device for the mobile unit according to claim 1, wherein, when generating the second sound data from the first sound data, the generation unit performs processing for repeating a sound of a predetermined period included in the notification sound, on the location of sound falling.
 3. The notification device for the mobile unit according to claim 1, wherein the light source drive control unit changes at least one or more of chroma and brightness of light emitted from the light source unit in sync with an intensity of a sound expressed by the second sound data.
 4. The notification device for the mobile unit according to claim 1, wherein the generation unit further generates the second sound data on which sound rising processing control and sound falling processing control as the predetermined processing, the sound rising processing control being performed in response to time passage during a sound rising period included in the cycle, the sound falling processing control being performed in response to time passage during a sound falling period included in the cycle, the sound falling processing control bringing a smaller variation per unit of time than that during the sound rising period.
 5. The notification device for the mobile unit according to claim 1, wherein the generation unit generates the second sound data on which the predetermined processing is performed, based on speed information that indicates a speed at which the mobile unit moves.
 6. The notification device for a mobile unit according to claim 1, further comprising an acquisition unit that acquires brightness information that indicates brightness around the mobile unit, wherein the light source drive control unit adjusts at least one or more of chroma and brightness of light emitted by the light source unit, based on the brightness information acquired by the acquisition unit. 